U.S. patent application number 15/956056 was filed with the patent office on 2018-10-18 for transflective film for electro-optic elements.
The applicant listed for this patent is Gentex Corporation. Invention is credited to William L. Tonar.
Application Number | 20180299728 15/956056 |
Document ID | / |
Family ID | 63790546 |
Filed Date | 2018-10-18 |
United States Patent
Application |
20180299728 |
Kind Code |
A1 |
Tonar; William L. |
October 18, 2018 |
TRANSFLECTIVE FILM FOR ELECTRO-OPTIC ELEMENTS
Abstract
An electro-optic element includes a first substrate defining
first and second surfaces. The second surface includes a first
electrically conductive layer. A second substrate defines third and
fourth surfaces. The third surface includes a second electrically
conductive layer. A primary seal is disposed between the first and
second substrates. The seal and the first and second substrates
define a cavity therebetween. An electro-optic material is disposed
in the cavity. The electro-optic material being variably
transmissive such that the electro-optic element is operable
between substantially clear and darkened states. A transflective
film includes a liquid crystal material. The transflective film has
a thickness of from about 6 .mu.m to about 24 .mu.m. An adhesion
layer is positioned between the transflective film and the second
substrate. An alignment layer is positioned between the
transflective film and the adhesion layer.
Inventors: |
Tonar; William L.; (Holland,
MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Gentex Corporation |
Zeeland |
MI |
US |
|
|
Family ID: |
63790546 |
Appl. No.: |
15/956056 |
Filed: |
April 18, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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62486586 |
Apr 18, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02F 1/133555 20130101;
G02F 1/172 20130101; G02F 1/15 20130101; G02F 2201/343 20130101;
B60R 1/088 20130101; G02F 1/1339 20130101; G02F 1/17 20130101 |
International
Class: |
G02F 1/1335 20060101
G02F001/1335; G02F 1/1339 20060101 G02F001/1339; G02F 1/1337
20060101 G02F001/1337; G02F 1/1343 20060101 G02F001/1343; G02F
1/137 20060101 G02F001/137; C09J 7/38 20060101 C09J007/38 |
Claims
1. An electro-optic element comprising: a first substrate defining
first and second surfaces, wherein the second surface comprises a
first electrically conductive layer; a second substrate defining
third and fourth surfaces, wherein the third surface comprises a
second electrically conductive layer; a primary seal disposed
between the first and second substrates, wherein the seal and the
first and second substrates define a cavity therebetween; an
electro-optic material disposed in the cavity, the electro-optic
material being variably transmissive such that the electro-optic
element is operable between substantially clear and darkened
states; a transflective film comprising a liquid crystal material,
wherein the transflective film has a thickness of from about 6
.mu.m to about 24 .mu.m; an adhesion layer positioned between the
transflective film and the second substrate; and an alignment layer
positioned between the transflective film and the adhesion
layer.
2. The electro-optic element of claim 1, wherein the transflective
film is in contact with at least one of the first and second
electrically conductive layers.
3. The electro-optic element of claim 1, wherein the transflective
film is in contact with the electro-optic material.
4. The electro-optic element of claim 1, wherein the transflective
film comprises an average roughness of less than about 18 nm.
5. The electro-optic element of claim 4, wherein the transflective
film comprises an average roughness of less than about 15 nm.
6. The electro-optic element of claim 5, wherein the transflective
film comprises an average roughness of less than about 10 nm.
7. The electro-optic element of claim 1, wherein the transflective
film comprises a plurality of sublayers, wherein each of the
sublayers has a thickness of from about 0.5 .mu.m and about 5.0
.mu.m.
8. An electro-optic element comprising: a first substrate defining
first and second surfaces, wherein the second surface comprises a
first electrically conductive layer; a second substrate defining
third and fourth surfaces, wherein the third surface comprises a
second electrically conductive layer; a primary seal disposed
between the first and second substrates, wherein the seal and the
first and second substrates define a cavity therebetween; an
electro-optic material disposed in the cavity, the electro-optic
material being variably transmissive such that the electro-optic
element is operable between substantially clear and darkened
states; a transflective film comprising a liquid crystal material,
wherein the transflective film comprises an average roughness of
less than about 18 nm; and an adhesion layer positioned between the
transflective film and the second substrate.
9. The electro-optic element of claim 8, wherein the electro-optic
material is an electrochromic material.
10. The electro-optic element of claim 8, wherein the transflective
layer is in contact with the second electrically conductive
layer.
11. The electro-optic element of claim 8, wherein the transflective
film is configured to reflect circularly polarized light.
12. The electro-optic element of claim 11, further comprising: an
alignment layer positioned between the transflective film and the
adhesion layer.
13. The electro-optic element of claim 8, further comprising: an
adhesion layer positioned between the transflective film and at
least one of the first and second substrates.
14. The electro-optic element of claim 8, wherein a waviness of the
transflective film is less than about 0.20.
15. The electro-optic element of claim 14, wherein a waviness of
the transflective film is less than about 0.15.
16. The electro-optic element of claim 15, wherein a waviness of
the transflective film is less than about 0.10.
17. An electro-optic element comprising: a first substrate defining
first and second surfaces; a second substrate defining third and
fourth surfaces; a primary seal disposed between the first and
second substrates, wherein the seal and the first and second
substrates define a cavity therebetween; an electro-optic material
disposed in the cavity, wherein the electro-optic material is
variably transmissive; and a transflective film comprising a liquid
crystal material, wherein the transflective film comprises an
average roughness of less than about 18 nm and wherein a waviness
of the transflective film is less than about 0.38.
18. The electro-optic element of claim 17, further comprising: an
adhesion layer positioned between the transflective film and the
second substrate.
19. The electro-optic element of claim 18, wherein the adhesion
layer comprises a silane material.
20. The electro-optic element of claim 19, wherein the
transflective layer comprises a plurality of layers, further
wherein each of the layers is configured to reflect a different
wavelength band of light.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of and priority to U.S.
Provisional Patent Application No. 62/486,586, filed on Apr. 18,
2017, entitled TRANSFLECTIVE FILM FOR ELECTRO-OPTIC ELEMENTS, the
entire disclosure of which is hereby incorporated herein by
reference.
FIELD OF THE DISCLOSURE
[0002] The present disclosure generally relates to electro-optic
elements, and more particularly to electro-optic elements
incorporating transflective films.
BACKGROUND OF THE DISCLOSURE
[0003] Electro-optic elements may be used to reflect and/or
transmit light. Accordingly, a single layer which may reflect and
transmit different wavelengths of light may be advantageous.
SUMMARY OF THE DISCLOSURE
[0004] According to at least one aspect of the present disclosure,
an electro-optic element includes a first substrate defining first
and second surfaces. The second surface includes a first
electrically conductive layer. A second substrate defines third and
fourth surfaces. The third surface includes a second electrically
conductive layer. A primary seal is disposed between the first and
second substrates. The seal and the first and second substrates
define a cavity therebetween. An electro-optic material is disposed
in the cavity. The electro-optic material being variably
transmissive such that the electro-optic element is operable
between substantially clear and darkened states. A transflective
film includes a liquid crystal material. The transflective film has
a thickness of from about 6 .mu.m to about 24 .mu.m. An adhesion
layer is positioned between the transflective film and the second
substrate. An alignment layer is positioned between the
transflective film and the adhesion layer.
[0005] According to one aspect of the present disclosure, an
electro-optic element includes a first substrate defining first and
second surfaces. The second surface includes a first electrically
conductive layer. A second substrate defines third and fourth
surfaces. The third surface includes a second electrically
conductive layer. A primary seal is disposed between the first and
second substrates. The seal and the first and second substrates
define a cavity therebetween. An electro-optic material is disposed
in the cavity. The electro-optic material being variably
transmissive such that the electro-optic element is operable
between substantially clear and darkened states. A transflective
film includes a liquid crystal material. The transflective film
includes an average roughness of less than about 18 nm. An adhesion
layer is positioned between the transflective film and the second
substrate.
[0006] According to one aspect of the present disclosure, an
electro-optic element includes a first substrate defining first and
second surfaces. A second substrate defines third and fourth
surfaces. A primary seal is disposed between the first and second
substrates. The seal and the first and second substrates define a
cavity therebetween. An electro-optic material is disposed in the
cavity. The electro-optic material is variably transmissive. A
transflective film includes a liquid crystal material. The
transflective film includes an average roughness of less than about
18 nm and wherein a waviness of the transflective film is less than
about 0.38.
[0007] These and other features, advantages, and objects of the
present invention will be further understood and appreciated by
those skilled in the art by reference to the following
specification, claims, and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The following is a description of the figures in the
accompanying drawings. The figures are not necessarily to scale,
and certain features and certain views of the figures may be shown
exaggerated in scale or in schematic in the interest of clarity and
conciseness.
[0009] FIG. 1 is a general illustration of multi-passenger vehicles
incorporating electro-optic elements;
[0010] FIG. 2 is a top perspective exploded view of a rearview
mirror assembly, according to at least one example;
[0011] FIG. 3A is a cross-sectional view taken at line IIIA of FIG.
2, according to at least one example; and
[0012] FIG. 3B is a cross-sectional view taken at line IIIB of FIG.
2, according to another example.
DETAILED DESCRIPTION OF EMBODIMENTS
[0013] Additional features and advantages of the invention will be
set forth in the detailed description which follows and will be
apparent to those skilled in the art from the description or
recognized by practicing the invention as described in the
following description together with the claims and appended
drawings.
[0014] As used herein, the term "and/or," when used in a list of
two or more items, means that any one of the listed items can be
employed by itself, or any combination of two or more of the listed
items, can be employed. For example, if a composition is described
as containing components A, B, and/or C, the composition can
contain A alone; B alone; C alone; A and B in combination; A and C
in combination; B and C in combination; or A, B, and C in
combination.
[0015] In this document, relational terms, such as first and
second, top and bottom, and the like, are used solely to
distinguish one entity or action from another entity or action,
without necessarily requiring or implying any actual such
relationship or order between such entities or actions. The terms
"comprises," "comprising," or any other variation thereof, are
intended to cover a non-exclusive inclusion, such that a process,
method, article, or apparatus that comprises a list of elements
does not include only those elements but may include other elements
not expressly listed or inherent to such process, method, article,
or apparatus. An element preceded by "comprises . . . a" does not,
without more constraints, preclude the existence of additional
identical elements in the process, method, article, or apparatus
that comprises the element.
[0016] Referring now to FIGS. 1-3B, reference numeral 14 generally
designates an electro-optic element. The electro-optic element 14
includes a first substrate 18 defining a first surface 18A and a
second surface 18B. The second surface 18B includes a first
electrically conductive layer 22. A second substrate 26 defines a
third surface 26A and a fourth surface 26B. The third surface 26A
includes a second electrically conductive layer 30. A primary seal
34 is disposed between the first and second substrates 18, 26. The
seal 34 and the first and second substrates 18, 26 define a cavity
38 therebetween. An electro-optic material 42 is disposed in the
cavity 38. The electro-optic material 42 responds to an applied
voltage such that the electro-optic element 14 is operable between
substantially clear and darkened states. In other words, the
electro-optic material 42 may be variably transmissive. A
transflective film 46 includes a liquid crystal material. The
electro-optic element 14 may further include a liquid crystal
alignment layer 50 and/or an adhesion layer 52.
[0017] Referring now to FIG. 1, the electro-optic element 14 may be
implemented in an aircraft 58, a bus 62 and/or a train car 66.
Other vehicles are possible locations for the electro-optic element
14. Further, the electro-optic element may be implemented in
buildings and/or other structures.
[0018] Referring now to FIG. 2, the electro-optic element 14 may
also be applied to a mirror assembly 74. The mirror assembly 74 can
be an interior rearview assembly positioned within an interior of a
vehicle. When the mirror assembly 74 is an interior rearview
assembly, the mirror assembly 74 may be connected to a mount 78,
which is adapted to be mounted inside the vehicle in a location
proximate to or on a front windshield of the vehicle. It will be
understood that the present disclosure is equally applicable to
exterior mirrors, as well as other optical assemblies incorporating
electro-optic elements 14.
[0019] Referring now to FIG. 3A, the first substrate 18 may include
a variety of materials transparent in the visible region of the
electromagnetic spectrum including soda-lime float glass,
EAGLE.RTM. glass, alkaline earth boro-aluminosilacate glass,
GORILLA.RTM. glass, alkali-aluminosilicate glass, chemically
strengthened glass, insulated glass, tempered glass, sapphire,
optical crystals, diamond, quartz, ceramics, polymers or plastics.
The second substrate 26 may include the same materials as the first
substrate 18, but may not need to be transparent and may include
polymers, metals, glass, ceramics, and/or composites. The first and
second substrates 18, 26 may have a thickness from about 0.1 mm to
about 3.0 mm, from about 0.5 mm to about 2.2 mm, or from about 0.8
mm to about 1.6 mm. In some examples, the thicknesses of the first
and second substrates 18, 26 may differ from one another.
Furthermore, a reflector or reflection enhancement layer may be
located on either third or fourth surfaces 26A, 26B of the second
substrate 26, depending upon the type of electro-optic element 14.
The reflector or reflection enhancement layer may cover part, or
all of either the third or fourth surfaces 26A, 26B. The first and
second substrates 18, 26 may take a variety of shapes including
square, rectangular, circular, oblong and combinations thereof.
According to various examples, the first and/or second substrates
18, 26 may have a curvature across the length and/or width (i.e., a
vertical or horizontal axis). According to various examples, the
first substrate 18 may be wider, larger and/or longer, relative to
the second substrate 26 such that an overhang is defined around a
portion, a majority, or an entirety of the electro-optic element
14. Further, the overhang may vary in width around the perimeter of
the electro-optic element 14.
[0020] A first conductive electrode portion 90 and a second
conductive electrode portion 94 applied to the second surface 18B
cooperate to define the first electrically conductive layer 22. The
first and second conductive electrode portions 90, 94 are
substantially electrically insulated from one another via a first
isolation area 98. The first isolation area 98 cooperates with a
portion of the primary seal 34 to define the second conductive
electrode portion 94 and a second spectral filter portion 102, each
substantially electrically insulated from the first conductive
electrode portion 90 and a first spectral filter portion 106. This
configuration allows for placement of an electrically conductive
material 110 adjacent to the primary seal 34. The electrically
conductive material 110 may be formed from an electrically
conductive material, conductive solder, a conductive epoxy (e.g.,
silver epoxy), a wire and/or combinations thereof. A first
electrical clip 114 is in contact with the electrically conductive
material 110 and is further in electrical communication with a
third conductive electrode portion 118 and the electro-optic
material 42 disposed within the cavity 38. Electrical energy is
passed through the first electrical clip 114, through the
electrically conductive material 110 and across a third spectral
filter portion 122 into the first electrically conductive layer
22.
[0021] The third conductive electrode portion 118 and a fourth
conductive electrode portion 126 are shown proximate the third
surface 26A and are electrically insulated via a second isolation
area 130. The third and fourth conductive electrode portions 118,
126 cooperate to define the second electrically conductive layer
30. The second isolation area 130 cooperates with a portion of the
primary seal 34 to define the fourth conductive electrode portion
126 that is substantially electrically insulated from the third
conductive electrode portion 118. A second electrical clip 134 is
in electrical communication with the fourth conductive electrode
portion 126 and the electro-optic material 42. The first and second
electrically conductive layers 22, 30 may include a transparent
conductor such as a transparent metal oxide (e.g.,
indium-tin-oxide, F:SnO.sub.2, ZnO, IZO), carbon (graphene and/or
graphite) and/or a conductive metal mesh (e.g., nanowires). In
indium-tin-oxide examples, the first and second electrically
conductive layers 22, 30 may have a sheet resistance of between
about 1 ohms/sq and about 100 ohms/sq.
[0022] The primary seal 34 traverses an approximate perimeter of,
and is configured to cooperate with, the first and second
substrates 18, 26 to define the cavity 38 as substantially
hermetic. The cavity 38 may have a spacing between the first and
second substrates 18, 26 of less than or equal to about 500 .mu.m,
400 .mu.m, 300 .mu.m, 200 .mu.m, 100 .mu.m, 90 .mu.m, 75 .mu.m, 50
.mu.m, 40 .mu.m, 35 .mu.m, or less than or equal to about 20 .mu.m.
The primary seal 34 may be applied to the first or second
substrates 18, 26 by methods commonly used in the liquid crystal
display (LCD) industry, such as by silk-screening or dispensing.
Additional information related to forming a seal between a first
and second substrate can be found in U.S. Pat. No. 5,790,298,
entitled "METHOD OF FORMING OPTICALLY TRANSPARENT SEAL AND SEAL
FORMED BY SAID METHOD," which is hereby incorporated herein by
reference in its entirety. The electro-optic material 42 is
disposed within the cavity 38, as shown in FIG. 3A. The first and
third spectral filter portions 106, 122 extend inboard from the
primary seal 34 into the cavity 38 sufficiently far enough to
generally conceal the primary seal 34 from a viewer.
[0023] The illustrated electro-optic element 14 has the
electro-optic material 42 positioned between the first substrate 18
and the second substrate 26 in the cavity 38. According to one
example, the electro-optic element 14 may be a liquid crystal
device, including a liquid crystal medium (e.g., the electro-optic
material 42), configured to attenuate light transmitted through the
electro-optic element 14. In another example, the electro-optic
element 14 may be a suspended particle device. In some examples,
the electro-optic material 42 may be an electrochromic material. In
such examples, the electro-optic material 42 may be a solution
phase material as disclosed in U.S. Pat. No. 4,902,108 entitled
"SINGLE-COMPARTMENT, SELF-ERASING, SOLUTION-PHASE ELECTROCHROMIC
DEVICES, SOLUTIONS FOR USE THEREIN, AND USES THEREOF" and U.S. Pat.
No. 5,278,693 entitled "TINTED SOLUTION-PHASE ELECTROCHROMIC
MIRRORS," commonly assigned to Gentex Corporation, both of which
are hereby incorporated in their entirety herein. In other
examples, the electro-optic material 42 may be in a solid-state. In
such a configuration, the electro-optic element 14 discussed herein
may be configured to be transitioned between substantially
transparent and substantially darkened states.
[0024] Referring now to FIGS. 3A and 3B, the transflective film 46
may be positioned within the electro-optic element 14 (e.g.,
proximate the second and/or third surfaces 18B, 26A) and/or on an
exterior surface (e.g., the first and/or fourth surfaces 18A, 26B).
In examples where the transflective film 46 is positioned on one of
the exterior surfaces, an optional overcoat or overmold may be
applied to protect the transflective film 46 from environmental
exposure. The transflective film 46 can be placed on both the first
and second substrates 18, 26. In such an example, the film 46 on
the first substrate 18 may reflect one type of polarization and the
film 46 on the second substrate 26 may reflect a second type of
polarization. In examples where the transflective film 46 is
positioned within the electro-optic element 14, the film 46 may be
in contact with at least one of the first and second substrates 18,
26 (e.g., positioned on the second surface 18B and/or the third
surface 26A) the first electrically conductive layer 22, the second
electrically conductive layer 30, the alignment layer 50 and/or the
adhesion layer 52. The first and/or second electrically conductive
layers 22, 30 may be positioned between the transflective film 46
and the respective first and second substrates 18, 26 or the first
and/or second electrically conductive layers 22, 30 can be adjacent
to and in electrical contact with electro-optic material 42. In the
depicted example of FIG. 3A, the transflective film 46 is in
contact with the electro-optic material 42 and the second
electrically conductive layer 30. In such an example, the
electro-optic material 42 may be a liquid crystal, or a field
effect, material. In the depicted example of FIG. 3B, the alignment
layer 50 and the adhesion layer 52 are positioned between the
transflective film 46 and the third surface 26A, but it will be
understood that the film 46 may be positioned directly on the third
surface 26A. Further, it will be understood that the construction
and ordering of the alignment layer 50, the adhesion layer 52 and
the transflective film 46 may be equally applied to the second
surface 18B. The transflective film 46 is depicted as extending
between the seal 34 and the second substrate 26, but it will be
understood that the transflective film 46 may only extend between
the seal 34.
[0025] The transflective film 46 may be composed of a plurality of
layers having different optical properties (e.g., reflectance,
transmission and scattering) as explained in greater detail below.
Further, the optical properties of the transflective film 46 may
vary across, or within, the transflective film 46. For example, a
first portion of the transflective film 46 may be configured to
scatter or reflect a specific wavelength band of light while a
second portion may not. The transflective film 46 may include
layers that reflect one polarization of light and transmit a second
polarization of light. The transflective film 46 may contain a
layer or layers that act as a quarter wave plate that will convert
linear polarized light to circularly polarized light or vice versa.
The transflective layer 46 may be configured to reflect both
polarizations of a specific wavelength band of light. The
transflective layer 46 could be configured to scatter a specific
wavelength band of light. The layers can be composed of a material
that has liquid crystalline properties. In such examples, the
liquid material forms a solid film. In examples of the
transflective film 46 incorporates the liquid crystal material, the
liquid crystal material may be a cholesteric liquid crystal
material. In other words, the liquid crystal polymers may have a
helical structure known as a pitch. In such examples, the
transflective film 46 may have a pitch from 250 nm to about 400
nm.
[0026] If the transflective film 46 is used as a specular reflector
(e.g., for example in an automatic mirror application) it may be
advantageous that the reflected image is substantially preserved
and free from undesirable distortion. It may be difficult to
laminate a pre-formed film to a substrate without incorporating
undesirable distortion. As such, casting the transflective film 46
directly onto an optically acceptable substrate such as glass may
be advantageous. According to various examples, the liquid crystal
examples of the transflective film 46 may be cast or coated
directly onto one of the first and/or second substrates 18, 26, or
may be cast or coated onto any of the aforementioned layers (e.g.,
the first and second electrically conductive layers 22, 30,
alignment layer 50 and/or adhesion layer 52). In liquid crystal
examples of the transflective film 46, the film 46 may be composed
of multiple layers (e.g., each cast or coated separately in
sequence). The transflective film 46 may have a thickness of from
about 6 .mu.m and about 24 .mu.m, or from about 8 .mu.m and about
16 .mu.m. In a specific example, the transflective film 46 may have
a thickness of about 12 .mu.m. The transflective film 46 may have
an arithmetic average surface roughness value from about 0.1 nm to
about 70 nm, or from about 0.2 nm to about 50 nm, or from about 0.5
nm to about 20 nm. In specific examples, the arithmetic average
surface roughness of the film 46 may be less than or equal to about
18 nm, 15 nm, 10 nm or less than or equal to about 5 nm. The
transflective film 46 may have waviness. The waviness may be
presented as a measurement of the maximum difference (e.g., in nm)
between a peak and a valley of the transflective film 46 which is
divided by the distance (e.g., in nm) between the peak and the
valley. Accordingly, the waviness value may be unitless. The
waviness may have a value from about 0.01 to about 0.9, or from
about 0.1 to about 0.5. In specific examples, the waviness of the
film 46 may be less than or equal to about 0.38, 0.2, 0.15 or less
than or equal to about 0.1.
[0027] The transflective film 46 may be composed of a plurality of
layers, each having different or the same optical properties (e.g.,
wavelength band of reflection, absorption, scattering and/or
transmission). The transflective film 46 may have between 1 and
about 10 layers. In a specific example, the film 46 may include
four layers. It will be understood that each layer may contain
sublayers which aid in the polarization, reflection, scattering,
transmission and/or absorption of light. Each of the sublayers may
have a thickness of from about 0.5 .mu.m and about 5.0 .mu.m.
Further, it will be understood that the transflective film 46 may
be used in conjunction with a quarter-wave plate to convert linear
polarized light to circularly polarized light or vice versa.
[0028] The transflective layer 46 may conform to a variety of
environmental tests. For example, the transflective film 46 may
survive temperature ranges from about -40.degree. C. to about
85.degree. C. for up to and beyond 1000 hours. Further, the
transflective film 46 may survive high humidity tests (e.g.,
60.degree. C. with 90% relative humidity). The transflective layer
46 may resist thermal shock (e.g., a temperature swing from about
-40.degree. C. to about 85.degree. C. over the course of about 30
minutes). The transflective layer 46 may also survive a variety of
ultraviolet light tests.
[0029] According to various examples, the transflective film 46 may
be configured to reflect, transmit, scatter and/or absorb various
polarizations and/or wavelengths of light. The transflective film
46 may have a reflectance of one or more wavelength bands of the
electromagnetic spectrum and/or polarizations. For example, the
transflective film 46 may reflect a specific color or band (e.g.,
ultraviolet, visible, near-infrared, infrared) of electromagnetic
radiation or type of polarization (e.g., vertical, horizontal,
clockwise circular and/or counterclockwise circular). The
transflective film 46 may reflect greater than or equal to about
1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or greater
than or equal to about 99% of one or more wavelength bands of the
electromagnetic spectrum or types of polarization.
[0030] The transflective film 46 may have a transmittance of one or
more wavelength bands of the electromagnetic spectrum and/or
polarizations. For example, the transflective film 46 may transmit
a specific color or band of electromagnetic radiation or a
plurality of colors and bands. Further, the transflective film 46
may transmit one or more types of polarization (e.g., vertical or s
polarization, horizontal or p polarization, clockwise circular
polarization and/or counterclockwise circular polarization). It
will be understood that the transflective film 46 may also convert
one polarization (e.g., linear) to another polarization (e.g.,
circular). The transflective film 46 may transmit or convert
greater than or equal to about 1%, 5%, 10%, 20%, 30%, 40%, 50%,
60%, 70%, 80%, 90%, or greater than or equal to about 99% of one or
more wavelength bands of the electromagnetic spectrum or types of
polarization.
[0031] The transflective film 46 may be configured to scatter one
or more wavelength bands of the electromagnetic spectrum or types
of polarization. For example, the transflective film 46 may scatter
a specific polarization or color or band (e.g., ultraviolet,
visible, near-infrared, infrared) of electromagnetic radiation. The
transflective film 46 may scatter greater than or equal to about
1%, 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or greater
than or equal to about 99% of one or more polarizations and/or
wavelength bands of the electromagnetic spectrum. It will be
understood that the transflective film 46 may be capable of
reflecting, scattering, absorbing and/or transmitting different
polarization and wavelengths of light simultaneously. For example,
the transflective film 46 may be configured to reflect and/or
scatter red clockwise polarized light. In examples where the
transflective film 46 includes multiple layers or sections, each of
the layers or sections may reflect and/or scatter a different
combination of band and polarization of light. For example, a first
layer or area of the transflective film 46 may be configured to
reflect or scatter yellow clockwise polarized light while a second
layer or area may be configured to reflect or scatter green
counterclockwise polarized light. As such, the transflective film
46 may be oriented to cause color mixing between reflected,
scattered and/or transmitted light.
[0032] The adhesion layer 52 may include one or more adhesion
promoting materials to secure the transflective film 46 and/or the
alignment layer 50 to the first and/or second substrates 18, 26.
The adhesion promoting materials of the adhesion layer 52 may
include an optical coupling adhesive, silanes, a primer and/or
other adhesive materials. The adhesion layer 52 may be applied via
dip coating, solution coating, spray coating and/or other
application methods. The application method and material of the
transflective film 46 that are chosen may form a film that
preserves the desirable optical properties of the substrate (e.g.,
one of the first and/or second substrates 18, 26) and minimally
contribute undesirable distortion to the image reflected from the
transflective film 46. The adhesion layer 52 may have a thickness
of less than or equal to about 20 .mu.m, 10 .mu.m or less than or
equal to about 5 .mu.m. The adhesion layer 52 may follow the
optical surface of the surface it is positioned on (e.g., the first
or second substrates 18, 26) so as to not interfere with the
surface's optical flatness.
[0033] The alignment layer 50 is depicted as positioned between the
transflective film 46 and the adhesion layer 52, but it will be
understood that the alignment layer 50 may be applied directly to
the first and/or second substrates 18, 26. The alignment layer 50
may be composed of a material configured to align molecules within
liquid crystal examples of the transflective film 46 or the
electro-optic material 42. In a specific example, the alignment
layer 50 may induce homogeneous and/or homeotropic liquid crystal
alignment and be polymer based like polyimide or polyvinyl alcohol
or a surface treatment like an organic silane coating which may be
doped. The alignment layer 50 may be used to provide the liquid
crystal molecules with a specific pre-tilt angle. It will be
understood that any material capable of providing a specific
pre-tilt angle or surface orientation to the liquid crystal
molecules may be utilized without departing from the teachings
provided herein.
[0034] Use of the present disclosure may offer a variety of
advantages. First, by casting the transflective film 46 directly
onto the first and second substrates 18, 26, onto the second
electrically conductive layer 30, the alignment layer 50 and/or the
adhesion layer 52, use of transfer sheets which transport the
transflective film 46 from a manufacturing site to the
electro-optic element 14 may be eliminated. Further, the direct
casting of the transflective film 46 onto the electro-optic element
14 may eliminate a costly and time-intensive lamination process
which may also induce defects which can reduce reflected image
quality. Second, as the transflective film 46 may reflect, scatter,
transmit and/or absorb various polarizations and wavelengths of
light, the transflective film 46 may be advantageously used in a
variety of applications to reflect undesired wavelengths of light
(e.g., infrared from a vehicle application), adjust a transmitted
color (e.g., reflect or scatter undesired colors) and the like.
Third, the transflective film 46 may be incorporated inside or on
an exterior of the electro-optic element 14 which may be
advantageous in providing design flexibility to the electro-optic
element 14 and also protect the film 46 from mechanical and
environmental exposure change. Fourth, electro-optic elements 14
including the transflective film 46 may be used in conjunction with
polarized eyewear.
Examples
[0035] Referring now to Table 1, provided are surface roughness and
surface waviness values for a plurality samples of films (e.g., the
transflective film 46) positioned on glass plates (e.g., one of the
first and second substrates 18, 26). The roughness and surface
waviness values of the films were measured by white light
interferometry at 10.times. magnification using an instrument
similar to a Zygo ZeGage Plus.
[0036] The first sample is a base bare glass plate used for
lamination samples. The second sample is a cholesteric based
reflective polarizer film laminated onto glass with a thin liquid
acrylic adhesive layer. The third sample is a cholesteric based
reflective polarizer film laminated onto glass with a 0.001'' thick
acrylic pressure sensitive adhesive layer and the fourth sample is
a cholesteric based reflective polarizer film laminated onto glass
with a 0.002'' thick acrylic pressure sensitive adhesive layer. The
fifth sample is a bare glass plate used for casting examples. The
sixth sample is the glass substrate having single 1 um thick
polymer film solution (e.g., the liquid crystal examples of the
transflective film 46) cast onto glass by a spin process. The
seventh sample is a 1 um thick film followed by a 4 um thick film
both cast onto glass by a spin process.
[0037] From the data provided in Table 1, it can be shown that the
surfaces of films cast onto a high-quality optical substrate will
tend to replicate the high-quality surface of the optical substrate
more closely than solid films that are laminated onto glass. As
such, casting of optical coatings onto the plates may be
advantageous in decreasing an arithmetic average surface roughness
as well as waviness of the resulting coatings.
TABLE-US-00001 TABLE 1 Waviness Sample Material Roughness (Ra)
(PV/wavelength) 1 Base Glass (Lam) 1.10 nm 0.09 2 Laminated Liquid
20.16 nm 0.62 Acrylic 3 Laminated 1 mil PSA 27.51 nm 0.41 4
Laminated 2 mil PSA 57.6 nm 0.83 5 Base Glass (Cast) 0.79 nm 0.021
6 One Cast Coating 1.02 nm 0.048 7 Two Cast Coatings 6.28 nm
0.144
[0038] Modifications of the disclosure will occur to those skilled
in the art and to those who make or use the disclosure. Therefore,
it is understood that the embodiments shown in the drawings and
described above are merely for illustrative purposes and not
intended to limit the scope of the disclosure, which is defined by
the following claims, as interpreted according to the principles of
patent law, including the doctrine of equivalents.
[0039] It will be understood by one having ordinary skill in the
art that construction of the described disclosure, and other
components, is not limited to any specific material. Other
exemplary embodiments of the disclosure disclosed herein may be
formed from a wide variety of materials, unless described otherwise
herein.
[0040] For purposes of this disclosure, the term "coupled" (in all
of its forms: couple, coupling, coupled, etc.) generally means the
joining of two components (electrical or mechanical) directly or
indirectly to one another. Such joining may be stationary in nature
or movable in nature. Such joining may be achieved with the two
components (electrical or mechanical) and any additional
intermediate members being integrally formed as a single unitary
body with one another or with the two components. Such joining may
be permanent in nature, or may be removable or releasable in
nature, unless otherwise stated.
[0041] As used herein, the term "about" means that amounts, sizes,
formulations, parameters, and other quantities and characteristics
are not and need not be exact, but may be approximate and/or larger
or smaller, as desired, reflecting tolerances, conversion factors,
rounding off, measurement error and the like, and other factors
known to those of skill in the art. When the term "about" is used
in describing a value or an end-point of a range, the disclosure
should be understood to include the specific value or end-point
referred to. Whether or not a numerical value or end-point of a
range in the specification recites "about," the numerical value or
end-point of a range is intended to include two embodiments: one
modified by "about," and one not modified by "about." It will be
further understood that the endpoints of each of the ranges are
significant both in relation to the other endpoint, and
independently of the other endpoint.
[0042] The terms "substantial," "substantially," and variations
thereof as used herein are intended to note that a described
feature is equal or approximately equal to a value or description.
For example, a "substantially planar" surface is intended to denote
a surface that is planar or approximately planar. Moreover,
"substantially" is intended to denote that two values are equal or
approximately equal. In some embodiments, "substantially" may
denote values within about 10% of each other, such as within about
5% of each other, or within about 2% of each other.
[0043] It is also important to note that the construction and
arrangement of the elements of the disclosure, as shown in the
exemplary embodiments, is illustrative only. Although only a few
embodiments of the present innovations have been described in
detail in this disclosure, those skilled in the art who review this
disclosure will readily appreciate that many modifications are
possible (e.g., variations in sizes, dimensions, structures, shapes
and proportions of the various elements, values of parameters,
mounting arrangements, use of materials, colors, orientations,
etc.) without materially departing from the novel teachings and
advantages of the subject matter recited. For example, elements
shown as integrally formed may be constructed of multiple parts, or
elements shown as multiple parts may be integrally formed, the
operation of the interfaces may be reversed or otherwise varied,
the length or width of the structures, and/or members, or
connectors, or other elements of the system, may be varied, and the
nature or numeral of adjustment positions provided between the
elements may be varied. It should be noted that the elements and/or
assemblies of the system may be constructed from any of a wide
variety of materials that provide sufficient strength or
durability, in any of a wide variety of colors, textures, and
combinations. Accordingly, all such modifications are intended to
be included within the scope of the present innovations. Other
substitutions, modifications, changes, and omissions may be made in
the design, operating conditions, and arrangement of the desired
and other exemplary embodiments without departing from the spirit
of the present innovations.
[0044] It will be understood that any described processes, or steps
within described processes, may be combined with other disclosed
processes or steps to form structures within the scope of the
present disclosure. The exemplary structures and processes
disclosed herein are for illustrative purposes and are not to be
construed as limiting.
[0045] It is also to be understood that variations and
modifications can be made on the aforementioned structures and
methods without departing from the concepts of the present
disclosure, and, further, it is to be understood that such concepts
are intended to be covered by the following claims, unless these
claims, by their language, expressly state otherwise. Further, the
claims, as set forth below, are incorporated into and constitute
part of this Detailed Description.
* * * * *